Mixamo import edit clothing textures
Okay, so I figure out a solution for now.  I was able to use texture paint and switch to vertex mode to paint each part of the armature (shirt, body, tie, etc..)
These changes were permanent.   FYI it is not as good as textures but I am still trying to figure out how to change the colour of the original textures.  If I figure it out I will update.